Superscalarity is largely pointless yes, given that memory access between threads is almost always a pain, so two of them rarely process the same data and can't

Superscalarity is largely pointless yes, given that memory access between threads is almost always a pain, so two of them rarely process the same data and can't take advantage of using a single core's cache at the same time. It doesn't even make much sense in concept. But multicore performance does matter significantly unless you're on a microcontroller running only one process on your entire machine. Just Chrome launches a quarter million processes by itself.